Skip to main content

Full text of "The manufacture and properties of iron and steel"

See other formats


FUEL.                                              167
SEC. IXc.—Miscellaneous fuels.—There are some fuels which are essentially local in their character like natural gas and oil, but which are extensively used in metallurgical operations.
(a)  Natural gas:
In the favored district lying just west of the Alleghenies in Pennsylvania, West Virginia, Ohio and Indiana, natural gas has been used for all kinds of heating from about 1884 until the present time. The composition varies in different wells, but in all cases the gas is made up of members of the paraffine series, with not over one-half of 1 per cent, of carbonic acid (C02) and from 2 to 12 per cent, of nitrogen. By ultimate analysis it gives 70 per cent, of carbon and 23 per cent, of hydrogen, while, by ordinary methods, it shows from 67 to 93 per cent, of marsh gas, the remainder being principally hydrogen. At first this gas was passed through regenerative chambers, but this was discontinued owing to the deposition of soot and to the discovery that sufficient heat was obtained by leading the gas directly to the ports and burning it with air which had been regenerated in the usual manner. Of late years the supply of gas has been decreasing and the demand has been met by the constant drilling of new wells in new territory. There is a limit to this method, and it would seem that before many years this fuel will cease to be a factor in the larger operations of a steel works.
(b)  Petroleum:
Crude oil may be transformed into a vapor by atomizing with steam and superheating the mixture, but unless exposed for some time to a yellow heat it remains a vapor, and hence will condense if carried through long, uncovered pipes or introduced into the cold valves of a regenerative furnace. It may be 'put into the chambers at some point where the temperature is high, and in this way condensation will be prevented as well as the waste heat he utilized. There is a partial molecular rearrangement with the steam, but the action is far from perfect, for, after passing through 20 feet of small brick flues at a yellow heat, the product may contain 20 per cent, of free aqueous vapor. The mixture of oil vapor and steam may be burned in a muffle, for, after the walls are red hot, there is a reciprocal sustentation of heat; but the use in reverberatory furnaces is wasteful, since the action is sluggish. Even in regenerative practice a charge of cold stock retards combustion much more with oil than with coal gas, and even at maximum temperatures the